The most recent Surface is called the Surface Book 2 and it is excellent, but of course pretty expensive.
You'll need to choose between the 13 inch and the 15 inch model, with both offering various processor, storage and memory combinations.
The 15 inch Surface Book 2 provides 16GB of RAM and up to 1TB of storage for the highest spec machine. Additionally, it comes with a GTX 1060 chip with 6GB VRAM, so it is five times faster than the original Surface Book, Microsoft claim.
If a traditional laptop isn't for you, then the Surface Pro (2017) is a powerhouse tablet with attachable keyboard (although, you'll have to buy this separately). This tablet offers a Core i7-7660U, 16GB of RAM and a 512GB Samsung KUS040202M SSD. Its performance is very impressive, more than enough to run numerous business tasks.
Another one to consider is Microsoft's own Surface Laptop, which depending on the model, could set you back anywhere from £979 to £2,149.
Its cheapest model houses the Intel Core i5 processor, 4GB of RAM, and a 128GB SSD, while its top-end laptop comes with the Intel Core i7, 16GB of RAM and a 512GB SSD.
Finally, there's always the Surface Pro 4. It's not new, but it is still a solid machine. If you want to save a bit of money and still get a very capable machine, this is it.